curl --request GET \
  --url http://localhost:8000/buyers/lookup

{
  "found": true,
  "is_frequent": true,
  "buyer": {
    "id": "<string>",
    "id_type": "<string>",
    "legal_name": "<string>",
    "trade_name": "<string>",
    "contributor_status": "<string>",
    "contributor_type": "<string>",
    "address": "<string>"
  }
}